Without a doubt, an effective root canal treatment can extend the life of a tooth for many years. But sometimes even a well-maintained tooth can fall prey to disease months or even years after a root canal treatment. While there are a number of reasons to account for this failure, a common one is so tiny it could have easily been missed during the first treatment.

A root canal is an open space within the tooth that contains the pulp. The pulp is a connective tissue with a network of nerve fibers connected to the root that alert the brain to environmental changes involving the tooth. It is most important during the tooth’s early development, but becomes less important as we age. The pulp is susceptible to infection from tooth decay or periodontal (gum) disease, which if left untreated can threaten the tooth’s survival. During a root canal treatment, we enter these spaces, clear out the diseased pulp and fill the canal with a bio-compatible filling; we then seal it off to deter further decay.

The treatment could ultimately fail, though, because of accessory or lateral canals missed during the procedure. Like a tree with smaller branches growing out of its larger limbs, accessory canals are smaller access ways that branch off of the main root canals. These accessory canals, which can occur anywhere along a main canal, can be quite small and not easily detected during an initial root canal treatment. They are especially susceptible to infection due to gum disease if they open into the periodontal membrane, the main attachment point between teeth and bone.

If we suspect the presence of accessory canals (either initially or after ensuing problems following a root canal treatment), this could require the skills of an endodontist, a dentist who specializes in the treatment of a tooth’s interior. Accessory canals are treated in much the same way as larger canals, but may require an endodontist’s specialized microscopic equipment and filling techniques. Effective treatment of these smaller accessory canals will certainly improve the chances of a successful, long-term outcome for the tooth.